Less than six hours before he was scheduled to take the stage at Red Rocks Amphitheatre to perform for a sold-out crowd of 9,500 fans Wednesday night, Jack White’s silver Mercedes van rolled up to Isdajo Automotive on West Colfax Avenue.

White — one of the most celebrated musicians of the past 10 years for his work with the White Stripes, the Raconteurs, the Dead Weather and most recently, as a solo artist — played a 20-minute impromptu concert for about 300 fans on the sizzling pavement near the service station.

At 3 p.m. Wednesday, White’s mobile record store sent a Twitter message giving fans a half-hour jump on the time and location of the “B” show. Within minutes, dozens were already on the scene — standing on cars, clinging to fences, furiously texting the news to friends.

It was a climactic end to a social media manhunt for White’s Denver whereabouts that lasted the better part of two days. On Tuesday, White was spotted eating breakfast at the Delectable Egg in LoDo and shopping with his family at Rockmount Ranch Wear. He stopped in for a drink at the Cruise Room inside the Oxford Hotel, then was seen sauntering up the 16th Street mall. Around 6 p.m. Tuesday, White rented out the entirety of Lucky Strike Lanes in Denver Pavilions for his son’s birthday party.

Through it all, just a single photograph of the enigmatic White surfaced to prove that he was really in Denver at all. Such is the way White prefers to operate in the public sphere — infamously “banning” cameraphones during his concerts.

Nevertheless, nearly every attendee at the “B” show attempted to capture every moment of this four-song set of bluesy garage rock, which began with the White Stripes’ “Black Math” and ended with “Ball and Biscuit.”

Service station owner Manuel Bonilla said that members of White’s crew had stopped in Isdajo Automotive two hours earlier asking permission to put on the show.

“They told me it was going to be a band,” Bonilla said. “They didn’t mention any names.”

Minutes after White and his backing musicians piled in the van and headed west on Colfax, Bonilla admitted he still had no idea who Jack White was.

“I just figured that it’s going to satisfy a bunch of people,” he said, laughing.

Follow our news and updates on Twitter, our whereabouts on Foursquare and our relationship status on Facebook. Or send us a telegram.

John Hendrickson is the managing editor of Reverb and a multimedia journalist at The Denver Post. Follow him on Twitter, if that’s what you’re into.

Seth McConnell is a member of YourHub at The Denver Post and a new contributor to Reverb.